---
id: CVE-2026-80545
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  s390/zcrypt: Improve EP11 CPRB length and overflow checks

  The xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input
  validation, creating security vulnerabiliti…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  s390/zcrypt: Improve EP11 CPRB length and overflow checks

  The xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input
  validation, creating security vulnerabiliti…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 20b0b0159390fa5c00a435195649680fefda81e0 <
    f463f474773aa49ed1d6087d95d44cea7099fdc7
  - >-
    Linux >= e2c6d91eb8b1533753755f07803e47eceed263d0 <
    2976b9d2e716c7e5487ca7c29a7bd076cf9adf08
  - >-
    Linux >= e2c6d91eb8b1533753755f07803e47eceed263d0 <
    17ac0bc866fc624cd05f022dcd8b730c0af11bb1
  - Linux 7.1
published: '2026-08-26'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T11:17:50.903'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80545'
references:
  - url: 'https://git.kernel.org/stable/c/17ac0bc866fc624cd05f022dcd8b730c0af11bb1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2976b9d2e716c7e5487ca7c29a7bd076cf9adf08'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f463f474773aa49ed1d6087d95d44cea7099fdc7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00183
epssPercentile: 0.07311
ingestedAt: '2026-10-15T11:00:41.665Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

s390/zcrypt: Improve EP11 CPRB length and overflow checks

The xcrb_msg_to_type6_ep11cprb_msgx() function lacks proper input
validation, creating security vulnerabilities:
1. Missing minimum size validation: The ep11_cprb structure and
   subsequent payload fields (pld_tag, pld_lenfmt) are copied from
   userspace without verifying sufficient buffer length.
2. Arithmetic overflow in length calculations: CEIL4 alignment could
   overflow, bypassing size checks and enabling buffer overflows.
3. The payload is asn1 encoded but the function just uses a simple c
   struct overlay to access some fields of the payload.

Fix by using size_t for length calculations, adding U32_MAX boundary
checks after alignment, and validating minimum request size and
minimum reply size before copying from userspace. Do a very simple
asn1 parsing of the payload up to the function value field.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.